Cedar hottub with decking

Greetings! I'm looking to build a 6' diameter, 4' deep outdoor cedar hot tub. Clear cedar dimensional lumber is EXPENSIVE, so I was considering grabbing decking from places like home depot over time until I accumulate enough basically clear lengths for the staves.  My concern is about the fact that decking is generally 1" thick, while dim lumber is 1.5". I am wondering if anyone has tried this? Could it simply be a matter if adding a couple more steel bands around the tub to support the staves, or will this material just flex too much?

1” should be fine with 4 bands. I made one out of 1” cypress. The extra thickness would be helpful at the bottom to side joint, but not totally necessary. The thing to look out for when picking is no knots and no sap wood. Not even a little bit. If you can’t tell, assume it’s sap wood. Also, look for Slick Seam. It’s a wood boat type product; it’s your friend.

Good luck.